ASICs requite a lot of up front capital to design and manufacture. ASICs also only really matter when prices are low and performance/watt matters. There's also

ASICs requite a lot of up front capital to design and manufacture. ASICs also only really matter when prices are low and performance/watt matters. There's also limited supply too. The popular gpu algorithm is ethereum, who's heading algorithm (ethash) is memory hard, so muhh of the performance relies on the speed of commercial DRAM chips so the difference between ASICs and GPUs are not as great. Along with the lower incentive as ethereum plans to move to proof of stake ASICs for ethereum are not as popular or common.