It is caused by current market situation,
Mainly because the market would not crash if altcoins are not overvalued, imagine how much they increase during the last bull run, and that's what we are experiencing now, as what goes up must come down, however, always think of an opportunity to buy again as the pump and dump are in play now so it will result to assets being undervalued.
projects that have revolutionary ideas are waiting for better sentiment because they understand that now they will not collect enough funds for their projects.
This projects will be appreciated more when BTC are on the rise or the bull run comes again as when btc is stable, they can sprinkle their investment to altcoins as they have some good buffter by transferring to BTC when dump happens again for altcoins.