You can poke fun at its bland pronunciation and appearance, but it suits it, and while the OED lists only three distinct senses of "bleak" in its adjectival form, and overall its meaning is quite narrow, they are all wonderfully dreary. First we have bleak as in pale or devoid of color, which is generally applied to plants or a person's complexion and carries implications of ill health. This usage of bleak is considered obsolete. Apparently more lively (hah) definitions: barren as in lacking in vegetation and thus exposed to the elements, cold as in cold and windy weather (these first two senses are often blended together, with "bleak" describing a barren and windswept landscape) and, in a figurative sense, devoid of warmth or cheer.
Ahhh, bleak..the perfect, no-frills word for my favorite everything. Its etymology is unclear, but it may come from the Old Norse word bleikr, meaning pale, from which "bleach" is also derived.