No doglover.
The one often goes by the name of Siberian squill and the other as glory of the snow.
Am assuming their rapid spreading is also related to the fact that they are both poisonous.
Mind you daffodils are poisonous too, but, to my knowledge, daffodils don't spread by seeding.
I agree with you about gardeners and spreading plants, at one level,
but, more generally about perennials, a problem is that many only bloom for two or three weeks.
Consequently, if you want ongoing colour you need lots of different plants that bloom at different times of the growing season.
An aggressively spreading plant, of one type, does so at the expense of other less aggressive plants.
Reducing the variety of plants in a perennial bed, reduces the amount of ongoing (and changing) colour.
