> For instance a waste of time of font designers

No more so than right now.

> selecting a reasonable subset of bazyllion random, singular pictures to draw and test is a major headache.

Right, because there[0] were[1] no[2] "bazyllion[3] random[4], singular[5] pictures[6] to[7] draw[8] and[9] test[10]" dating back to Unicode 1.0[11] before and Unicode 7.0 changes everything.

[0] http://en.wikipedia.org/wiki/Mathematical_alphanumeric_symbo...

[1] http://en.wikipedia.org/wiki/Mahjong#Unicode

[2] http://en.wikipedia.org/wiki/Dominoes#Dominoes_in_Unicode

[3] http://en.wikipedia.org/wiki/Playing_Cards_(Unicode_block)

[4] http://en.wikipedia.org/wiki/Musical_Symbols_(Unicode_block)

[5] http://en.wikipedia.org/wiki/Arrow_(symbol)#Arrows_in_Unicod...

[6] http://en.wikipedia.org/wiki/Optical_Character_Recognition_(...

[7] http://en.wikipedia.org/wiki/Geometric_Shapes

[8] http://en.wikipedia.org/wiki/Unicode_Dingbats

[9] http://en.wikipedia.org/wiki/Phonetic_Extensions

[10] http://en.wikipedia.org/wiki/Miscellaneous_Technical_(Unicod...

[11] http://en.wikipedia.org/wiki/Box_Drawing_(Unicode_block)