This would increase the CPU overhead of drawing the tilemap by a factor of 100 or more, since it would no longer be able to draw regions of tiles in one go (see this blog post). It would likely also introduce new glitches at edges meeting transparency (where there is no tile), since the tile area rendered is too large.
As ever the workaround is: letterbox integer scale, point sampling, pixel rounding. Seams should never show up with those settings. I've been thinking for a long time of a high-performance workaround for the seams, and I can't come up with anything so far. Meanwhile it works with the right settings. It's not that I don't care, it's a difficult technical problem.