I come from a Microsoft background - so would build an entire MS Access database, with front end interfaces, business logic, database, queries, reports and even integrations to other applications like MS Excel , terminal emulators and Lotus Notes in just two languages - VBA & Access SQL - and even the I wouldn't write much SQL as there's a query builder!
Perhaps some development environments shield you from this, but intertwining PHP & HTML can be a bit of an issue - it just feels messy. Echoing out HTML & dealing with echoing text containing double and single quotes (<<<END END is good, but doesn't look very nice as you can't indent it nicely). It's good though that you don't have to concatenate to include variables in a string.
Lots of people have their opinions on which language I should be developing in “Java is the hot language at the moment..” “you want to be developing iPhone apps - learn Objective C!” “Android is the future - learn whatever language that is...” I worry about becoming a Jack of all trades - master of none...!