The problem to us is that, in the general view of astrology, many of the things represented by the modern Pluto, are incompatible with most of the traditional teachings.
1) First of all, is what we consider the "aberrations", such as pluto ruling Scorpio (instead of Mars), or ruling sex, death, and the many more things that have been claimed to it. Like we've said in some posts, most of the attributes linked to pluto are borrowed (rather stolen) from other planets; mainly from Mars and Saturn. When we look at the many things pluto represents to modernists, we see it as a weird mix of the other planets.
2) Second, is the way this aberrations are presented to us. No reasoning or explanation behind them. It is "just because". No one explains why pluto does any of these things. No one gives evidence but saying stuff like:"pluto transiting your 2nd house, that is why you have money problems".
3) Third, is the interchangable nature and the many more significations that pluto recieves. Some go from treating pluto as an extreme malefic (associated with violence) or as a good benefic (positive and idealistic changes). It is as if authors on the subject apply anything that crosses their minds into pluto. Seems rather odd that the planet can be both good or bad, and mostly at the authors will. If someone needs to explain something good they use pluto, something bad, they use pluto too. It seems to me that pluto is rather used as a tool to explain things that don't seem to fit into modern astrology.
4) Fourth, as we said many times: the 7 classical planets explain everything. Pluto really adds nothing new. So why use something that can't give us more info?
5) Fifth and final, pluto doesn't reflect light, can't be seen with the naked eye. It is a small asteroid, with many more asteroids like him orbiting the sun. If you are going to use pluto, why not use Europa (jupiter's moon)?
We covered this in the first 3 pages so I won't go much into detail with it.
But pretty much, to us, pluto seems like a perfect solution for ignoring all the other stuff that needs to be accounted for. It seems like an easy solution for modern astrology to explain things that are complicated to explain.