I think the problem here is one that is common to many fields, Fortean and otherwise.
The term "cryptozoology" has widened in scope until it has become almost meaningless.
At one end of the spectrum are serious researchers who are seeking physical evidence to confirm or refute essentially credible witness evidence of unknown but plausible creatures.
At the other end, there are people who are excited by big scary monsters and will come up with pseudoscientific rationales for so called "cryptids" that would defy the laws of normal science. (Example: something roughly human sized and with wings sprouting out of its back could not generate enough lift to fly, so perhaps it is an inter-dimensional being.)
Between these extremes are various positions with varying degrees of credibility.
The problem is then that the people at the "rationalising" end of the spectrum use the word "cryptozoology" to add a spurious scientific respectability to their own area of interest and, in so doing, they cause an equal and opposite reaction in the general public. Someone with a genuine scientific interest in a plausible area of cryptozoology may find that his or her work is popularly lumped together with that of all the people who believe in werewolves and mothmen and the like.
In a similar way, anyone who tries to present a serious case for Loch Ness containing an "unknown species" will not get as far as describing a 6 foot eel or a subspecies of sturgeon before the journalist is already reaching for his or stock images of plesiosaurs towering over terrified highlanders.
Cryptozoology seems to encompass a wide range of disciplines and areas of interest including, but not limited to:
- Inquiries into credible reports of unknown species that would plausibly exist in the environment they are said to inhabit: an unknown species of ape in a large area of sparsely populated jungle, for example.
- Inquiries into credible reports of known species in alien environments. Big cats on Dartmoor, for example.
- Inquiries into widespread reports of creatures that are not necessarily impossible, but seem unlikely to have remained undiscovered for so long. Bigfoot, Sasquatch, Yeti, for example.
- Inquiries into the possibility that a known species assumed to be extinct may exist as a small surviving population in a remote area.
- Inquiries into credible reports of extreme examples of known species: an individual python or crocodile substantially larger than any previously killed, photographed, or captured.
- Interest in a possible factual basis for creatures described in myth or legend: species or individual animals that may have existed even if the stories have subsequently grown in the telling.
- Interest in strange and unknown creatures described in myth or legend, but with the clear understanding that this is a study of myth rather than of real things.
- Interest in creatures described in modern folk tales and news reports, but from a sociological perspective. This is the sensible position that "I know that Slenderman is a recently invented fictional entity, but it is fascinating to study how people have come to regard him as a real phenomenon."
- An apparent belief in weird and impossible creatures described in folk tales and news reports. Such a belief can always be rationalised by the believer. Inconsistencies in descriptions may be attributed to shape shifting ability. Breaches of the known laws of physics are attributed to some poorly-defined but convenient inter-dimensional origin. These are the people who may try to borrow credibility from those at the top of this list and, in so doing, discredit their serious scientific work.
Some people would lump all these together as cryptozoology. A purist might only admit the top 1, 2, or 3 on the list. The trouble is, it is not possible to stop someone else using a word to describe their particular field of interest. Maybe the purists need to come up with a more specific and less "nickable" word for their endeavours.
Meanwhile, I can't help feeling that if someone was searching the Amazon rain forest for a species of small dragonfly widely believed to be extinct, they would be an entomologist or naturalist, rather than a cryptozoologist. If they were looking for a species 5 foot tall ape known to the locals as "the old man of the forest" they would probably be called cryptozoologists. Strange.