Generally I agree, but for the pedantic there are other issues. Tabs at the beginning of lines aren't a problem. But, for example, it's common to see multi-line declarations of, let's say, a hash where each line looks like this:
key <tab> => <tab> value
This might look perfectly fine for someone using 8-width tabs, but it will most likely be screwy for anyone using 4-width tabs or smaller. The tab's location is calculated as the distance where the cursor position modulo the tab width is 0.
E.g. one key is 2 chars long and another is 5 chars long. You tabbed it using 8-width tabs. Looks fine. If someone loads it with 4-width tabs, they see the two lines aligned differently.
key <tab> => <tab> value
This might look perfectly fine for someone using 8-width tabs, but it will most likely be screwy for anyone using 4-width tabs or smaller. The tab's location is calculated as the distance where the cursor position modulo the tab width is 0.
E.g. one key is 2 chars long and another is 5 chars long. You tabbed it using 8-width tabs. Looks fine. If someone loads it with 4-width tabs, they see the two lines aligned differently.